如何处理IOS图像裁剪中的图像旋转问题

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【中文标题】如何处理IOS图像裁剪中的图像旋转问题【英文标题】:how to handle Image rotation issue in IOS image cropping 【发布时间】:2013-04-12 05:49:40 【问题描述】:

我正在开发与相机相关的应用程序。这里我正在从相机拍摄图像,需要对其进行裁剪,然后将其修复为图像视图。为了裁剪图像,我正在使用 OpenGL。我的问题是我在裁剪图像之后是旋转 180 度。但这并非一直发生。有时我会得到原始图像本身。

-(void)showResult

    NSLog(@"showResult called" );

    UIImage *imageCrop;
    float scaleCrop;
    if (_sourceImage.size.width >= IMAGEWIDTH)
    
        scaleCrop = IMAGEWIDTH / _sourceImage.size.width;
        imageCrop = [ImageCropViewController scaleImage:_sourceImage with:CGSizeMake(_sourceImage.size.width*scaleCrop, _sourceImage.size.height*scaleCrop)];
    
    else
    
        scaleCrop = 1;
        imageCrop = _sourceImage;
    


    float scale = _sourceImage.size.width / resizeImage.size.width * 2;
    IplImage *iplImage = [ImageCropViewController CreateIplImageFromUIImage:imageCrop] ;
    Quadrilateral rectan;

    rectan.point[0].x = _touchLayer.rectan.pointA.x*scale*scaleCrop;
    rectan.point[0].y = _touchLayer.rectan.pointA.y*scale*scaleCrop;

    rectan.point[1].x = _touchLayer.rectan.pointB.x*scale*scaleCrop;
    rectan.point[1].y = _touchLayer.rectan.pointB.y*scale*scaleCrop;

    rectan.point[2].x = _touchLayer.rectan.pointC.x*scale*scaleCrop;
    rectan.point[2].y = _touchLayer.rectan.pointC.y*scale*scaleCrop;

    rectan.point[3].x = _touchLayer.rectan.pointD.x*scale*scaleCrop;
    rectan.point[3].y = _touchLayer.rectan.pointD.y*scale*scaleCrop;

    IplImage* dest = cropDoc2(iplImage,rectan);

    IplImage *image = cvCreateImage(cvGetSize(dest), IPL_DEPTH_8U, dest->nChannels);
    cvCvtColor(dest, image, CV_BGR2RGB);
    cvReleaseImage(&dest);

    tempImage = [ImageCropViewController UIImageFromIplImage:image withImageOrientation:_sourceImage.imageOrientation];
    [self crop:tempImage];
    cvReleaseImage(&image);


之后调用下面的方法

+ (UIImage *)UIImageFromIplImage:(IplImage *)image withImageOrientation:(UIImageOrientation)orientation

    NSLog(@"UIImageFromIplImage called" );

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    NSData *data = [NSData dataWithBytes:image->imageData length:image->imageSize];
    CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
    CGImageRef imageRef = CGImageCreate(image->width, image->height, image->depth, image->depth * image->nChannels, image->widthStep, colorSpace, kCGImageAlphaNone|kCGBitmapByteOrderDefault, provider, NULL, false, kCGRenderingIntentDefault);
    UIImage *ret = [UIImage imageWithCGImage:imageRef scale:1 orientation:orientation];
    CGImageRelease(imageRef);
    CGDataProviderRelease(provider);
    CGColorSpaceRelease(colorSpace);
    return ret;

然后我根据我的要求旋转图像

-(void)crop:(UIImage*)image


    NSLog(@"crop called" );
   //Adjust the image size, to scale the image to 1013 of width
    float targetWidth = 1009.0f;
    float scale = targetWidth / image.size.width;
    float scaleheight = image.size.height * scale;
   UIImage *imageToSent = [ImageCropViewController scaleImage:image     with:CGSizeMake(targetWidth, scaleheight)];


if([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeLeft)


    NSLog(@"###########Image orientation is UIInterfaceOrientationLandscapeLeft###########");
    imageToSent = [[UIImage alloc] initWithCGImage:imageToSent.CGImage scale:1.0f orientation:UIImageOrientationDown];



NSData *imageData = UIImageJPEGRepresentation(imageToSent,0.75);
NSDate *now = [NSDate dateWithTimeIntervalSinceNow:0];
NSString *caldate = [now description];
appDelegate.imagefilePath= [NSString stringWithFormat:@"%@/%@.jpg", DOCUMENTS_FOLDER,caldate];
[imageData writeToFile:appDelegate.imagefilePath atomically:YES];

appDelegate.cropimage=imageToSent;

我没有找到出错的地方。这正在浪费我的时间。请帮助我。

提前致谢

【问题讨论】:

删除这个 if 并尝试 if([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationLandscapeLeft) 你为什么用这个? 【参考方案1】:

我有这个裁剪代码。你为什么使用openGL。这是我的代码。

- (UIImage *)cropImage : (UIImage*)myImage withRect:(CGRect)rect

      CGImageRef imageRef = CGImageCreateWithImageInRect([myImage CGImage], rect);
      UIImage *img = [UIImage imageWithCGImage:imageRef]; 
      CGImageRelease(imageRef);
      return img;

只要您想裁剪图像,只需调用此方法即可。此外,当您从相机或画廊拍摄图像(从本机相机应用程序拍摄的图像)时,您将获得旋转图像。使用此代码将其恢复为原始图像。

//----rotate image if picked from gallery or camera----//
- (UIImage *)scaleAndRotateImage:(UIImage *)image 

    NSLog(@"scaleAndRotateImage");
    static int kMaxResolution = 640; // this is the maximum resolution that you want to set for an image.

    CGImageRef imgRef = image.CGImage;
    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGAffineTransform transform = CGAffineTransformIdentity;
    CGRect bounds = CGRectMake(0, 0, width, height);
    if (width > kMaxResolution || height > kMaxResolution) 
        CGFloat ratio = width/height;
        if (ratio > 1) 
            bounds.size.width = kMaxResolution;
            bounds.size.height = bounds.size.width / ratio;
         else 
            bounds.size.height = kMaxResolution;
            bounds.size.width = bounds.size.height * ratio;
        
    

    CGFloat scaleRatio = bounds.size.width / width;
    CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
    CGFloat boundHeight;
    UIImageOrientation orient = image.imageOrientation;
    switch(orient) 
        case UIImageOrientationUp:
            transform = CGAffineTransformIdentity;
            break;
        case UIImageOrientationUpMirrored:
            transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            break;
        case UIImageOrientationDown:
            transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
            transform = CGAffineTransformScale(transform, 1.0, -1.0);
            break;
        case UIImageOrientationLeftMirrored:
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
            transform = CGAffineTransformScale(transform, -1.0, 1.0);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;
        case UIImageOrientationLeft:
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
            transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
            break;
        case UIImageOrientationRightMirrored:
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeScale(-1.0, 1.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;
        case UIImageOrientationRight:
            boundHeight = bounds.size.height;
            bounds.size.height = bounds.size.width;
            bounds.size.width = boundHeight;
            transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
            transform = CGAffineTransformRotate(transform, M_PI / 2.0);
            break;
        default:
            [NSException raise:NSInternalInconsistencyException 
                        format:@"Invalid image orientation"];
    

    UIGraphicsBeginImageContext(bounds.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) 
        CGContextScaleCTM(context, -scaleRatio, scaleRatio);
        CGContextTranslateCTM(context, -height, 0);
     else 
        CGContextScaleCTM(context, scaleRatio, -scaleRatio);
        CGContextTranslateCTM(context, 0, -height);
    
    CGContextConcatCTM(context, transform);
    CGContextDrawImage(UIGraphicsGetCurrentContext(), 
                       CGRectMake(0, 0, width, height), imgRef); 
    UIImage *returnImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return returnImage;

希望我能帮上忙。

【讨论】:

我们试过了,但我们需要为裁剪线/点设置动画,这就是我们使用 OpenGl 的原因 动画裁剪线是什么意思? 边缘点应该向任何方向移动,而不仅仅是方形/矩形

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